#pragma once

/**
 * a digital multi-gas sensor for indoor air quality monitoring
 * https://www.sciosense.com/wp-content/uploads/documents/SC-001224-DS-7-ENS160-Datasheet.pdf
 */
template <typename I2C> class ENS160 {
	
private:

	I2C& i2c;
	static constexpr const uint8_t ADDR1 = 0x52;
	static constexpr const uint8_t ADDR2 = 0x53;
	uint8_t ADDR;
	
	static constexpr const char* NAME = "ENS160";

	static constexpr const uint8_t REG_PART_ID = 0x00;
	static constexpr const uint8_t REG_OPMODE = 0x10;
	static constexpr const uint8_t REG_TEMP_IN = 0x13;
	static constexpr const uint8_t REG_RH_IN = 0x15;
	static constexpr const uint8_t REG_DEVICE_STATUS = 0x20;
	static constexpr const uint8_t REG_DATA_AQI = 0x21;
	static constexpr const uint8_t REG_DATA_TVOC = 0x22;
	static constexpr const uint8_t REG_DATA_ECO2 = 0x24;



public:

	enum class Mode : uint8_t {
		DEEP_SLEEP = 0x00,
		IDLE = 0x01,
		STANDARD = 0x02,
		RESET = 0xF0,
	};
	
	union Status {
		
		uint8_t raw;
		
		struct {
			uint8_t newgpr : 1;
			uint8_t newdat : 1;
			uint8_t valid : 2;
			uint8_t dummy : 2;
			uint8_t stater : 1;
			uint8_t statas : 1;
		} __attribute__((__packed__));
		
		bool isNormal() const {return valid == 0;}
		bool isWarmUp() const {return valid == 1;}
		bool isStartUp() const {return valid == 2;}
		bool isInvalid() const {return valid == 3;}
		
	} __attribute__((__packed__));
	
	union Result {
		
		uint8_t raw[6];
		
		struct {
			Status status;
			uint8_t aqi;
			uint16_t tvoc;
			uint16_t eco2;
		} __attribute__((__packed__));
		
	} __attribute__((__packed__));
	
public:

	ENS160(I2C& i2c, uint8_t addr = ADDR1) : i2c(i2c), ADDR(addr) {
		
	}
	
	/** always 0x01 0x60 */
	uint16_t getID() {
		uint16_t res = 0;
		i2c.readReg(ADDR, 0x00, 2, (uint8_t*)&res);
		return res;
	}
	
	/** switch the mode of operation */
	void setMode(Mode m) {
		i2c.writeReg8(ADDR, REG_OPMODE, (uint8_t)m);
		DELAY_MS(250);	// not mentioned in the data-sheet but important?
	}
	
	/** set the current ambient temperature - for compensation */
	void setTemp(float celsius) {
		float kelvin = celsius + 273.15;
		uint16_t tmp = (uint16_t) (kelvin * 64);
		i2c.writeReg(ADDR, REG_TEMP_IN, 2, (uint8_t*)&tmp);
	}
	
	/** set the current ambient humidity (in %) - for compensation */
	void setHumi(uint8_t humi) {
		uint16_t tmp = humi * 512;
		i2c.writeReg(ADDR, REG_RH_IN, 2, (uint8_t*)&tmp);
	}	
	
	/** status + aqi + tvoc + eco2 */
	Result getAll() {
		Result res;
		memset(res.raw, 0, 6);
		i2c.readReg(ADDR, REG_DEVICE_STATUS, 6, res.raw);
		res.status = getStatus();
		//res.aqi = getAQI();
		//res.tvoc = getTVOC();
		//res.eco2 = getECO2();
		return res;
	}
	
	Status getStatus() {
		Status res;
		res.raw = i2c.readReg8(ADDR, REG_DEVICE_STATUS);
		return res;
	}
		
	uint8_t getAQI() {
		uint8_t tmp = 0;
		i2c.readReg(ADDR, REG_DATA_AQI, 1, &tmp);
		return tmp & 0b111;
	}
	
	uint16_t getTVOC() {
		uint16_t tmp = 0;
		i2c.readReg(ADDR, REG_DATA_TVOC, 2, (uint8_t*)&tmp);
		return tmp;
	}
	
	uint16_t getECO2() {
		uint16_t tmp = 0;
		i2c.readReg(ADDR, REG_DATA_ECO2, 2, (uint8_t*)&tmp);
		return tmp;
	}
	

	
	/** is the device present on the bus? */
	bool isPresent() {
		return i2c.query(ADDR);
	}
			
};